Genic Male Sterile Wheat Line Research Articles

Regulation of carbohydrate metabolism during anther development in a thermo-sensitive genic male-sterile wheat line.

Bainong sterility (BNS) is a thermo-sensitive genic male sterile wheat line, characterised by anther fertility transformation in response to low temperature (LT) stress during meiosis, the failure of vacuole decomposition and the absence of starch accumulation in sterile bicellular pollen. Our study demonstrates that the late microspore (LM) stage marks the transition from the anther growth to anther maturation phase, characterised by the changes in anther structure, carbohydrate metabolism and the main transport pathway of sucrose (Suc). Fructan is a main storage polysaccharide in wheat anther, and its synthesis and remobilisation are crucial for anther development. Moreover, the process of pollen amylogenesis and the fate of the large vacuole in pollen are closely intertwined with fructan synthesis and remobilisation. LT disrupts the normal physiological metabolism of BNS anthers during meiosis, particularly affecting carbohydrate metabolism, thus determining the fate of male gametophytes and pollen abortion. Disruption of fructan synthesis and remobilisation regulation serves as a decisive event that results in anther abortion. Sterile pollen exhibits common traits of pollen starvation and impaired starch accumulation due to the inhibition of apoplastic transport starting from the LM stage, which is regulated by cell wall invertase TaIVR1 and Suc transporter TaSUT1.

Identification and verification of genes related to pollen development and male sterility induced by high temperature in the thermo-sensitive genic male sterile wheat line.

Bioinformatic analysis identified the function of genes regulating wheat fertility. Barley stripe mosaic virus-induced gene silencing verified that the genes TaMut11 and TaSF3 are involved in pollen development and related to fertility conversion. Environment-sensitive genic male sterility is of vital importance to hybrid vigor in crop production and breeding. Therefore, it is meaningful to study the function of the genes related to pollen development and male sterility, which is still not fully understand currently. In this study, YanZhan 4110S, a new thermo-sensitive genic male sterility wheat line, and its near-isogenic line YanZhan 4110 were analyzed. Through comparative transcriptome basic bioinformatics and weighted gene co-expression network to further identify some hub genes, the genes TaMut11 and TaSF3 associated with pollen development and male sterility induced by high-temperature were identified in YanZhan 4110S. Further verification through barley stripe mosaic virus-induced gene silencing elucidated that the silencing of TaMut11 and TaSF3 caused pollen abortion, finally resulting in the declination of fertility. These findings provided data on the abortive mechanism in environment-sensitive genic male sterility wheat.

QTL mapping of male sterility‐related traits in a photoperiod and temperature‐sensitive genic male sterile wheat line BS366

AbstractThe photoperiod/temperature‐sensitive genic male sterile (P/TGMS) character is important for use of heterosis in hybrid wheat. In the present study, the fertility of 172 doubled haploid (DH) lines derived from the cross between a P/TGMS wheat line BS366 and a restorer wheat line Baiyu149 was investigated under both fertile and sterile environments during three cropping seasons. The phenotype was recorded based on the international seed setting rate. A total of 167 SSR and 1,278 SNP markers were used to construct a linkage map, with a total length of 3,748.94 cM and an average marker interval of 2.59 cM. Three QTLs were identified and designated asQF.bhw‐2DS, QF.bhw‐4BSandQF.bhw‐7Al,explaining 6.9%–12.8%, 19.7%–25.6% and 7.2%–8.8% of the phenotypic variances, respectively. These results lay a good basis for application of male sterility‐related molecular markers in improvement of two‐line hybrid wheat breeding system.

Blocked synthesis of sporopollenin and jasmonic acid leads to pollen wall defects and anther indehiscence in genic male sterile wheat line 4110S at high temperatures.

Environment-sensitive genic male sterility is a valid tool for hybrid production and hybrid breeding, but there are no previous reports of the molecular mechanism of fertility conversion. In this study, RNA-seq, phenotypic and cytological observations, and physiological indexes were applied to analyze thermo-sensitive genic male sterility line 4110S under different temperature conditions to explore the fertility transformation mechanism. In total, 3420 differentially expressed genes (DEGs) were identified comprising 2331 upregulated genes and 1089 downregulated genes. The DEGs were apparently distributed among 54 Gene Ontology functional groups. The phenylpropanoid, long-chain fatty acid, and jasmonic acid (JA) biosynthesis pathways were related to male sterility, where their downregulation blocked the synthesis of sporopollenin and JA. Phenotypic and cytological analyses showed that pollen wall defects and anther indehiscence at high temperatures induced sterility. Moreover, enzyme-linked immunosorbent assay results indicated that the abundance of JA was lower in 4110S under restrictive conditions (high temperature) than permissive conditions (low temperature). A possible regulated network of pathways associated with male sterility was suggested. These results provided insights into the molecular mechanism of fertility conversion in the thermosensitive male sterility system.

Comparative transcriptome analysis identifies genes involved in the regulation of the pollen cytoskeleton in a genic male sterile wheat line

Male sterility is a widespread phenomenon in plants. The regulation of the pollen cytoskeleton is closely related to fertility in wheat. In this study, the distribution of the pollen cytoskeleton was observed by fluorescence staining in the conventional controlled wheat line CP806 and the genic male sterile wheat line BS366 throughout meiosis. The distribution of microfilaments and microtubules was disordered and asymmetrical in pollen cells of BS366, and the structure of the spindle body was unclear and nearly undetectable. Based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses, five cytoskeleton-related KEGG pathways, four GO terms, and 35 differentially expressed genes (DEGs) were identified, including eight genes assigned to GO functions and 27 genes assigned to KEGG pathways. Additionally, 86 differentially expressed transcription factors (TFs), belonging to seven TF families, were obtained. We performed qRT-PCR assays for four genes among the eight genes identified in GO enrichment analyses, eight genes among the 27 genes identified in KEGG pathway analyses, and seven TFs from seven TF families. All of these 19 candidate genes showed disparate expression patterns in CP806 and BS366, suggesting that these genes are involved in the regulation of the pollen cytoskeleton in BS366. In addition, we found lower levels of endogenous jasmonic acid (JA) and brassinolide (BR) in BS366 than that in CP806, suggesting that the biosynthetic pathways of JA and BR are abnormal in BS366. These findings provide gene resources for clarifying cytoskeleton-mediated male sterility in genic male sterile wheat lines.

Fertility Alternation of Thermo-photo-sensitive Genic Male Sterile Wheat Line C412S and Expression of Fertility Related <I>APRT </I>Gene

Fertility Alternation of Thermo-photo-sensitive Genic Male Sterile Wheat Line C412S and Expression of Fertility Related <I>APRT </I>Gene